Peer Reviewed Journal Articles (National) (FT)
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- ItemSkill development in marine fisheries: Some reflections on the issues and way outs(Indian Council of Agricultural Research, 2021)Indian fisheries sector is receiving increasing attention and policy support owing to the livelihood and foreign exchange potential of the sector apart from its nutritional significance. The Government of India has initiated ‘Blue Revolution’ to augment the fish production and to strengthen the fish based value chain. But, unequipped manpower is often highlighted as one of the major deterrents for leveraging the full potential in harvest and post-harvest fisheries sector, which is highly skill intensive in nature. The issue would emerge more serious in case of marine fisheries. In this paper, we attempted to deliberate on the issue of skill-deficit that would emerge in harvest and post-harvest sectors of marine fisheries sector in India, and suggest measures to address them.
- ItemSelectivity estimates for Sepiella inermis (Van Hasselt, 1835) in 40 mm diamond mesh codend trawl net(CSIR-NISCAIR, 2021)Cephalopods are mostly targeted by trawlers and Sepiella inermis (spineless cuttlefish), contributes about 2-4 percent of total cephalopod landings in India. Cephalopods accounted for 6.9 percent of total landings in Gujarat in 2018, with S. inermis accounting for approximately 1 %. The most common length of this species in the fishery is between 35 mm to 147 mm. The length at first sexual maturity varies along the coast, and recent estimates for west coast of India for this species is 48 and 55 mm for males and females, respectively. There are no estimates of trawl codend selectivity for this species and experiments were carried out using a 40 mm diamond mesh codend using covered codend method. The selection parameters for S. inermis were derived using SELECT methodology and the length at 50 % retention (L50)±(s.e.) was worked out as 36.2±1.2 mm and selection range as 19.9±2.1 mm. The selection factor and the selection ratio for the codend were worked out as 0.9 and 0.55, respectively. The suggested mesh size for the codend based on length at first sexual maturity (LFM) of females (55 mm) and males (48 mm) were estimated as 60 and 53 mm (diamond mesh), respectively. This is the first estimate of trawl selection for this species and operational parameters like towing speed, codend catch etc., that could influence selectivity were not considered and hence more studies by incorporating these factors will help in further refining the parameters of the selection curve.
- ItemPair Trawling vs. Otter Trawling: An evaluation of efficiency along the Southwest Coast of India(Society of Fisheries Technologists (India), 2021)In Karnataka, the trawling industry contributes significantly to fish landings. Though conventional otter trawlers account for the majority of trawl landings in the state, pair/bull trawling, which is prohibited, also during the post-monsoon season. There are no published reports on the specifications of the gear used or the changes operation, in the region over the last few years. A comparison of pair/ bull trawls and mid-water finfish otter trawls operating off the coast of Karnataka was conducted. The specifications for the gears were gathered from the gear fabrication units in Mangalore and Malpe. The pair trawl’s head rope (HR) measured 183–293 m in length, while the finfish otter trawl’s HR measured 99–110 m. The pair trawls had a mouth opening that was between 2.9–4.06 times that of the mid-water finfish otter trawls. Trawlers operating along the Karnataka coast conducted both pair and otter trawling during the same cruise, depending on the circumstances. The study indicates that the catch rate was significantly higher in pair trawls than in otter trawls. The average drag produced by pair trawls was calculated to be 6.74 tonnes at a speed of 3.0 kn, while the drag produced by otter trawls was only 2.28 tonnes at the same speed. The result of the study indicates that while the high fuel consumption of a pair trawling unit may negate some of the profits, the overall profit margin of the unit remains high during pair trawling, enticing fishermen to engage in clandestine pair trawling.Capping engine power, regulating gear size and operation and enforcing legal mesh sizes through stringent “monitoring, control and surveillance” mechanisms mitigate the negative impacts of pair trawling.
- ItemStructural and Operational Aspects of Fishing Traps of Meghalaya, North East India(Society of Fisheries Technologists (India), 2021)Fish traps are passive fishing gear which lured the fish either for food or shelter and get trapped through appropriate hard or soft structures. Documentation of these traditional fish trapping methods from the northeastern parts of India is limited. This study attempts to document the traditional fish trapping devices from four districts of Meghalaya with respect to its structure and operation. The depicted survey highlights 11 types of fish traps which were classified into three major categories such as tubular, basket and box traps. Average length of these documented traps ranged from 0.25- 1.5 m and mostly operated during monsoon and post-monsoon season in floodplain and low-lying areas like rice fields, ponds, shallow rivers and ditches. Murrels, minnows, barbs, mahseers and catfishes were the dominant fish catch from these gears. Most of the traps were fabricated with bamboo and locally available materials with a life span of more than 2-3 years. Results revealed that Khnu/Chiap, is the most popular and efficient trap with a CPUE of 2.5 kg day-1 trap-1. Documentation and the knowledge concerning the traditional gears will facilitate to improvise the fishing gears which will ultimately improve the livelihood of fishermen in the northeastern region of India.
- ItemEffect of Sunlight and UV Radiation on Mechanical Strength Properties of Nylon Netting Twines(Indian journal of textile research, 1984)The tensile strength properties of nylon netting twines of two specifications, viz. 210/1/2 and 210/2/3, were studied on exposure to natural sunlight and artificial ultraviolet radiation. Tauti's equation, which relates to the microbial deterioration of cotton twines, was found applicable to the present data from which the coefficients of deterioration (10 were evaluated in each case. The significance of sample-to-sample variation in the rate of deterioration of nylon twines was tested by covariance analysis